This invention relates to a method permitting wide range utilization of light energy, including a series of processes of accumulating and storing light energy in a medium and releasing the same therefrom at a desired instant.
When certain materials are irradiated by light, eigenstates of atoms constituting these materials are excited by absorbing light energy and transitions take place from a low energy state (E.sub.o) to high energy states (ex. E.sub.1) (cf. FIG. 1). To the contrary, when atoms are in excited states (E.sub.1, E.sub.2, E.sub.3, . . . ), interactions with other atoms cause transitions from the excited states to more stable energy states and energy differences between them (.DELTA.E.sub.1, .DELTA.E.sub.2, .DELTA.E.sub.3, . . . ) are emitted in the form of light having various frequencies (.nu..sub.1, .nu..sub.2, .nu..sub.3, . . . ). This relationship can be expressed as follows; EQU .DELTA.E.sub.1 =h.nu..sub.1, .nu.E.sub.2 =h.nu..sub.2, .nu.E.sub.3 =h.nu..sub.3, . . .
Now, if it were possible to lock the aforementioned excited states as they are (i.e. to forbid the transitions from the high energy states E.sub.1, E.sub.2, E.sub.3 . . . to the more stable ones in order to lock the excited states) and in addition to release the aforementioned excitation energy (i.e. to allow the transitions) at a desired instant, it would be feasible to accumulate and store light energy in a medium and to release it therefrom when needed for its utilization.
The inventors have found according to the results of their investigation that if states formed by addition, absorption, and the like to different kinds of atoms and molecules are utilized as storing medium besides eigenstates of light absorbing matter, it is possible to accumulate and store light energy in the storing medium and release it therefrom at a desired instant as mentioned above by controlling temperature of the light absorbing medium.
In the case where light energy is released in the form of light at a desired instant, it is possible to obtain regenerated light having a predetermined wavelength region by choosing the kind of atoms or molecules to be added to the light absorbing matter.
By choosing a light absorbing matter which emits visible light, regenerated light can be used or illuminated. By means of a suitable photo-electric converter regenerated light can be used also for electric energy production. Moreover, by using light absorbing matter having a large area, it is possible to accumulate and store light energy and to release it therefrom at a desired instant for a long period of time and in a continuous manner.
Thus this invention permits the accumulation of light energy in light absorbing matter owing to the excitation of matter to high energy states, and to lock the higher energy states in order to store absorbed light energy during a desired period of time. The invention is characterized in that light energy thus stored is released trigger means such as heat at a desired instant. In this way this invention allows wide range utilizations of solar light and other light energies by means of such technical contributions.
The object of this invention is, therefore, to provide a series of processes permitting the accumulation of light energy by irradiating a light absorbing matter, to store the energy therein and to release light energy thus stored at a desired instant.